/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */

package org.apache.isis.core.metamodel.spec.feature;

import java.util.Collection;
import java.util.Queue;

/**
 * Base interface for {@link OneToManyAssociation} only.
 * 
 * <p>
 * Introduced for symmetry with {@link OneToOneFeature}; if we ever support
 * collections as parameters then would also be the base interface for a
 * <tt>OneToManyActionParameter</tt>.
 * 
 * <p>
 * Is also the route up to the {@link ObjectFeature} superinterface.
 * 
 */
public interface OneToManyFeature extends ObjectFeature {

    public enum CollectionSemantics {
        LIST, ARRAY, SET, OTHER;

        /**
         * The corresponding class is not a subclass of {@link Collection}.
         */
        public boolean isArray() {
            return this == ARRAY;
        }

        public boolean isList() {
            return this == LIST;
        }

        public boolean isSet() {
            return this == SET;
        }

        /**
         * For example, {@link Queue}, or some other 3rdparty implementation of
         * {@link Collection}.
         */
        public boolean isOther() {
            return this == OTHER;
        }

        public boolean isListOrArray() {
            return isList() || isArray();
        }
    }

    CollectionSemantics getCollectionSemantics();
}
